1. Field of the Invention
The present invention relates to a printing apparatus, an information processing apparatus, a method for controlling the printing apparatus, a method for controlling the information processing apparatus, and a storage medium.
2. Description of the Related Art
A known printing apparatus is capable of performing rasterization, storage, printing, and other processing in parallel based on jobs transmitted from a plurality of host computers via a network. Such printing apparatuses include small- to medium-sized office apparatuses which enable a plurality of users to enter each individual print job and acquire a print result.
In addition to the above-mentioned apparatuses, some comparatively large-sized apparatuses are operated by a dedicated operator. With such printing apparatuses, print jobs are entered from a plurality of host computers and an operator replaces print sheets and changes the order of print jobs to increase the printing efficiency. Printing apparatuses of this kind are referred to as print on demand (POD) apparatuses. Some of conventional printing apparatuses enable specifying of not only the paper size and sheet feed stage but also the type of print medium (hereinafter referred to simply as medium) when paper to be fed is indicated. A media type refers to a name assigned to a set of paper characteristics such as the surface property, grammage, shape, and color. Each apparatus has specific media types defined therefor. “THICK PAPER”, “OHP SHEET”, “RECYCLED PAPER”, “COLORED PAPER”, and “COATED PAPER” are exemplary media types. In addition to using media types specifically defined for an apparatus, a user may define specific media and media types and register them in the apparatus.
Some of conventional printing apparatuses are known to have functions of automatic sheet feed stage selection and automatic sheet feed stage changeover.
Automatic sheet feed stage selection refers to a function of automatically selecting, if none of sheet feed stages is specified when a print job is started, a sheet feed stage most suitable for a specified sheet size and media type.
Automatic sheet feed stage changeover refers to a function of automatically changing, if paper in the current sheet feed stage runs out or falls below a certain paper amount during execution of a print job and paper feeding, the current sheet feed stage to another sheet feed stage storing the paper of the same size to continue printing.
Generally, an office user rarely uses special paper and often enters a print job (as illustrated in FIG. 4B) to a printing apparatus without specifying the media type. If the media type is not specified, the printing apparatus performs an operation predetermined for each model, for example, it selects the media type from plain paper, thin paper, recycled paper, colored paper, and thick paper before printing.
With respect to office apparatuses, since basically a small number of media types is supported and special paper is rarely placed on a sheet feed stage, there have been few problems even without media specification. Further, when using an apparatus operating on special paper, a print job for which the user explicitly specifies plain paper (as illustrated in FIG. 4C) feeds only plain paper but does not feed other media types, and therefore there have been no problems.
In the POD environment, it is not rare that a user specifies special paper. Inmost cases, the user specifies the media type for each page, or the user specifies a sheet feed stage and an operator prepares paper for the sheet feed stage. In such an environment, the user uses a print job (as illustrated in FIG. 4D) specifying a different media type for each page.
Japanese Patent Application Laid-Open No. 2007-57944 discusses a technique for not feeding paper from an open sheet feed stage as a method for avoiding using undesired paper if none of sheet feed stages is specified. This technique enables performing both automatic sheet feed stage selection and automatic sheet feed stage changeover only in a desired range of sheet feed stages.
In recent years, with the increase in printer engine speed and controller processing speed, office apparatuses have become comparable to large-sized POD models in performance while maintaining their small sizes.
Since a POD apparatus is large-sized and requires a large installation area, a backup apparatus cannot be easily installed. In some cases, a high-speed office apparatus is installed as a backup apparatus although the operating speed and durability are not equal to those of a specialized apparatus.
Accordingly, an apparatus called LitePOD model that combines a high-speed printer engine and controller hardware for office use with increased operability for operator has been put on the market. If the function of a high-speed office apparatus can be combined with the function of a POD apparatus in one machine, manufacturing cost is reduced, enabling users to utilize the apparatus at low prices.
Japanese Patent Application Laid-Open No. 2009-256076 discusses a technique for an image forming apparatus which groups a plurality of paper feed trays and, when one paper feed tray becomes empty, switches to another paper feed tray of the same group. The technique excludes from a group a paper feed tray storing paper having different paper attribute and includes the paper feed tray in a group having the same paper attribute.
In recent years, from the viewpoint of recycling, it has become necessary in offices to use different paper for each purpose, for example, recycled paper for in-house documents and draft printing, and plain paper for documents for external use. However, if a user enters a print job with “NO MEDIA SPECIFICATION”, in a case where both recycled paper and plain paper are usable, to an apparatus having a plurality of media types set therein, colored paper may be fed by the above-mentioned function of automatic sheet feed stage selection (problem a).
In an apparatus operated under the above-mentioned condition, if plain paper is explicitly specified in a print job, plain paper can be fed. However, when plain paper runs out, the function of automatic sheet feed stage changeover does not function and the apparatus stops (displaying a paper-out message) even if another sheet feed stage holds sufficient amount of recycled paper. This is because plain paper and recycled paper are recognized as different media types. In this case, the user needs to do some troublesome work, i.e., replace paper or forcibly change the target sheet feed stage (problem b).
The above-mentioned problems a and b can be avoided by using the technique discussed in Japanese Patent Application Laid-Open No. 2007-57944, by closing only the sheet feed stage storing required paper and opening other sheet feed stages. However, in the case of an office apparatus used by many users, except for a POD apparatus operated by a dedicated operator, it is troublesome and impractical that a user operates sheet feed stages before entering a print job.
As described above, even if one paper feed tray becomes empty, printing can be performed by switching to another paper feed tray of the same group by using the technique discussed in Japanese Patent Application Laid-Open No. 2009-256076. However, with the technique discussed in Japanese Patent Application Laid-Open No. 2009-256076, it is necessary to prepare a plurality of paper feed trays storing paper having the same paper attribute. In an environment where many different types of paper need to be set in paper feed trays, this technique cannot be applied because a number of paper feed trays is insufficient.
In an environment where a dedicated POD apparatus (specialized apparatus) is installed, an operator may reassign a print job to a backup LitePOD apparatus because of a tight schedule of the specialized apparatus. If the reassigned job requires paper supported only by the specialized apparatus, for example, one-sided coated paper 1 is demanded, the LitePOD apparatus not supporting one-sided coated paper 1 will generate an error or feed default paper, for example, plain paper.
In some cases, a user does not inevitably need to use one-sided coated paper 1 in the print job but may accept the use of one-sided coated paper 2 supported by the LitePOD apparatus. Even in this case, however, there is a problem that the LitePOD apparatus generates an error or feeds unintended paper (plain paper) and performs printing (problem c). Thus, if the printing apparatus does not have paper of the same media type as the one specified in the print job, the conventional technique has been unable to flexibly address this problem.
As mentioned above, from the viewpoint of recycling, there has been a demand for flexibly changing paper on a job basis, for example, recycled paper for draft printing and plain paper (and one-sided coated paper 1 for some pages) for documents for external use. However, the technique discussed in Japanese Patent Application Laid-Open No. 2009-256076 groups paper feed trays of a printing apparatus and therefore cannot flexibly change paper on a job basis (problem d).